o/D off or On when you drive.

If you drove a three speed automatic would drive around down one gear? Of course not, run in OD. You will get better fuel mileage and less wear on the engine if you do. It will not shift into fourth gear, OD, until you get up above 35 MPH. The tranny will shift down when it needs too. Take it out of OD when you want to run in a lower gear, just as you would with any other tranny.

mike

Leave OD on. The only time I turn OD off is when I'm driving in mountainous terrain and the tranny keeps going into and out of OD.

The OD is on all the time except in steep hilly driving with our Mystique (which has traction control). Might take it off in slippery conditions without.